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TROPICAL CYCLONE REPORT SUPER GONI

Written by Khan for Khan Storm Tracking

at a glance

Typhoon Goni, known in the as Super Typhoon Rolly, was a profoundly strong typhoon that made landfall as a Category 5 super typhoon on in the Philippines and in as a tropical storm.

P a g e | 2 Synoptic History

After devasted the Philippines days prior, a broad low-pressure system composed off the , on October 27, 2020. The Meteorological Agency had declared a new tropical depression, although KST estimates didn’t have Goni as a Tropical Depression at that time stamp. On the following day, the JTWC followed suit and declared the newly formed low a Tropical Depression, designating the system as “Tropical Depression 22W” at 9:00UTC. As the depression moved westward under favorable conditions, it intensified to a Tropical Storm, with the Japan Meteorological Agency naming the system “Goni” on the same day. On the 29th, Goni underwent and became a typhoon, at 9:30UTC, Goni entered the Philippine Area of Responsibility. On the following day, Goni continued rapid intensification and became a Category 5 Super Typhoon. After a brief eyewall replacement cyclone on the 30th, the system continued intensifying reaching a T-Number for 8.0. The JTWC went with a 170knots (195mph) peak estimate and a central pressure of 884mbar, while KST went with 175knots (200mph) and a pressure of 888mbar for the peak numbers for Goni. On October 31st 18:00UTC (2:00PHT November 1st), hours before the historic landfall in Catanduanes, the PAGASA upgraded Goni into a super typhoon. This was the second occasion PAGASA declared a as a super typhoon since it’s re- introduction of their revised tropical cyclone intensity scale, with the first being Haima in 2016. This was also the second time that the highest wind warning level, Signal #5, was raised in the Philippines as per the revised tropical cyclone wind signals. At 20:50UTC, Goni made a historic landfall on Bato, Catanduanes, Philippines, at peak intensity. Goni then made another landfall on at 23:20UTC and San Narciso, on November 1st 4:00 UTC. Goni then made its final Philippine landfall in Lobo, at 9:30UTC. As high wind shear and land interaction incremented, it caused Goni to rapidly weaken before it emerged into the South Sea as a weak tropical storm. Goni then moved westward over the as a minimal tropical storm before making landfall in Vietnam on November 6, the system then rapidly weaken after landfall, degrading into a remnant low.

P a g e | 3 ANALYSIS MAIN REASONINGS FOR 175KNOTS/888MBAR

Goni showed strong similarities in terms of structure, CDO ring and temperature on both IR and WV imagery with a tropical cyclone that KST rated a similar intensity to Goni based on surface observations, which is 2016. Meranti showed a similar eye temperature (22-27°c), full ring temp (around -80°c) and a WV eye temp similar to Goni. BEST TRACK DATA

Below is the best track analysis from Khan Storm Tracking for STY Goni:

LEGENDS: T – Tropical S – Subtropical M – Monsoonal P - Peak Intensity

Date (yy/mm/dd) Time (UTC) Latitude Longitude Wind (mph) Pressure (mb) Stage 20201025 6:00UTC 11.2N 144.4E 20 1009 Disturbance 20201025 12:00UTC 11.4N 143.6E 20 1009 Disturbance 20201025 18:00UTC 11.7N 143.1E 20 1007 Disturbance 20201026 00:00UTC 12.4N 142.7E 20 1007 Disturbance 20201026 06:00UTC 13.4N 142.4E 20 1007 Disturbance 20201026 12:00UTC 14.5N 142.0E 25 1007 Disturbance 20201026 18:00UTC 15.0N 141.8E 25 1007 Disturbance 20201027 00:00UTC 15.4N 141.7E 25 1007 Disturbance 20201027 06:00UTC 15.8N 141.4E 25 1006 Disturbance 20201027 12:00UTC 16.3N 141.0E 25 1006 Disturbance 20201027 18:00UTC 16.5N 140.7E 30 1006 Disturbance 20201028 00:00UTC 16.6N 140.1E 35 1005 T Depression 20201028 06:00UTC 16.6N 139.5E 35 1004 T Depression 20201028 12:00UTC 16.6N 138.5E 40 1000 T Storm 20201028 18:00UTC 16.6N 137.6E 50 1000 T Storm 20201029 00:00UTC 16.6N 136.7E 65 995 T Storm 20201029 06:00UTC 16.8N 135.7E 80 982 Category 1 20201029 12:00UTC 16.6N 134.5E 105 971 Category 2 20201029 18:00UTC 16.4N 133.4E 140 943 Category 4 20201030 00:00UTC 16.4N 132.7E 150 934 Category 4 P a g e | 4

Date (yy/mm/dd) Time (UTC) Latitude Longitude Wind (mph) Pressure (mb) Stage 20201030 06:00UTC 16.3N 131.6E 175 911 Category 5 20201030 12:00UTC 16.1N 130.9E 180 905 Category 5 20201030 18:00UTC 15.8N 129.9E 185 904 Category 5 20201031 00:00UTC 15.3N 128.8E 185 895 Category 5 20201031 06:00UTC 14.7N 127.6E 190 894 Category 5 20201031 12:00UTC 14.2N 126.5E 195 892 Category 5 20201031 18:00UTC 13.7N 125.1E 200 888 P - Category 5 20201101 00:00UTC 13.5N 123.6E 150 932 Category 4 20201101 06:00UTC 13.6N 122.5E 85 980 Category 1 20201101 12:00UTC 14.1N 121.2E 70 990 T Storm 20201101 18:00UTC 14.6N 119.8E 65 992 T Storm 20201102 00:00UTC 14.9N 118.9E 45 1002 T Storm 20201102 06:00UTC 15.1N 117.9E 35 1002 T Depression 20201102 12:00UTC 15.1N 116.9E 40 1002 T Storm 20201102 18:00UTC 15.1N 116.1E 40 1004 T Storm 20201103 00:00UTC 14.7N 115.4E 40 1004 T Storm 20201103 06:00UTC 14.7N 115.2E 40 1004 T Storm 20201103 12:00UTC 14.7N 114.7E 45 1004 T Storm 20201103 18:00UTC 14.6N 114.2E 40 1004 T Storm 20201104 00:00UTC 14.5N 113.7E 40 1004 T Storm 20201104 06:00UTC 14.4N 113.3E 50 1001 T Storm 20201104 12:00UTC 14.3N 113.0E 45 1002 T Storm 20201104 18:00UTC 14.2N 112.4E 45 1000 T Storm 20201105 00:00UTC 14.1N 111.8E 40 1002 T Storm 20201105 06:00UTC 14.0N 111.4E 40 1002 T Storm 20201105 12:00UTC 14.0N 111.0E 35 1005 T Depression 20201105 18:00UTC 14.0N 110.2E 35 1005 T Depression 20201106 00:00UTC 14.0N 109.2E 35 1007 T Depression 20201106 06:00UTC 14.3N 108.4E 30 1008 T Depression 20201106 12:00UTC 14.9N 107.0E 30 1008 T Depression 20201106 18:00UTC 15.4N 105.4E 25 1008 Remnants 20201107 00:00UTC - - - DISSIPATED - - -

TRACK MAP BY KST ESTIMATES P a g e | 5

IMPACTS PHILIPPINES

When Goni first made landfall on Catanduanes during peak intensity, it brought belligerent, catastrophic winds to areas near the tropical cyclone. Around 125 cities and towns were left without electricity after the storms passing. 1,612,893 individuals over 6 regions were affected by the typhoon. Around 16,900 hectares of cropland were damaged, affecting some 18,000 farmers. It is estimated that 66,000 metric tons of rice, corn, and other high value crops were damaged. overflowed by 6 ft (1.8 m) due to the rains brought by the typhoon, and nearly 3,000 families were forced to evacuate. Floods in reached the roofs of houses, trapping at least 300 families. The Batangas Risk Reduction and Management Council chief requested for more volunteers from regional government agencies to assist with emergency response. The floods subsided by 21:00 PHT on November 2, with 110 individuals having been rescued by the local disaster management team. In Marinduque, three municipalities experienced flooding, with Santa Cruz experiencing over 6 feet flood waters. By 8:00 PHT (0:00 UTC), power outages were widespread in the , as 10 electric cooperatives reported a loss of power caused by toppled electric posts and damaged transmission lines. Two evacuation centers lost their roofs from the force of the wind. In Legazpi, flash floods overwhelmed the local villages, and roads were blocked by debris from the mountains and lahar flow from Volcano. The lahar submerged at least 180 houses, as well as vehicles and livestock, in the locality of , as well as in , Santo Domingo, and . The nearby Basud Bridge, which connects the first and second districts of the P a g e | 6 province, was also destroyed and rendered impassable due to the lahar, while the famous were heavily flooded. The Civil Aviation Authority of the Philippines reported significant damage to Naga Airport and moderate damage to , along with the loss of contact with Virac Airport, the only airport serving the island of Catanduanes. The NDRRMC said a total of P8.47 billion (US$175.44 million) worth of roads, bridges, flood control systems, schools and government buildings were damaged in the Cordillera Administrative Region, National Capital Region, Ilocos, Valley, Central , (, Laguna, Batangas, Rizal and Quezon), (Mindoro, Marinduque, Romblon and Palawan), Bicol and . Flights and train operations resumed a day after the typhoon's landfall. As of November 11, the NDRRMC has reported ₱12.9 billion (US$266 million) of infrastructure damages, along with ₱5 billion (US$103 million) of agricultural damage, with a combined total of ₱17.9 billion (US$369 million). By December 10, total damage to agriculture and infrastructure was estimated at ₱20 billion (US$415 million), and 31 people were reported dead. VIETNAM

On November 5, Tropical Depression Goni made landfall in southern Bình Định, becoming the fifth tropical cyclone to strike the country in the previous 30 days. A person in Quảng Ngãi was swept away by floodwaters on November 6. Another sailor went missing on November 6 after the ship he was captaining sunk. Twenty houses in Quảng Nam Province collapsed into a river and a school was damaged. In Bình Định, 22 houses and infrastructures were destroyed by landslides and 108 hectares (270 acres) of croplands were damaged. Floods inundated a total of 1,074 houses. Roads in several areas were damaged by erosion and landslides, including parts of the Ho Chi Minh Highway. Damage in Bình Định Province from both Goni and Etau were calculated to be ₫543 billion (US$23.5 million). NAMING

Due to the extensive damage brought by the typhoon in the Philippines, the PAGASA announced that Rolly will be stricken from the rotating list of typhoon designations, and will no longer be used in the future. In January 2021, the PAGASA chose the name Romina as its supersession for the 2024 season. After the season, the Typhoon Committee announced that the name Goni, along with four others will be abstracted from the denominating lists, with supersessions to be announced in 2022. FINAL STATISTICS Wind Peak Pressure Accumulated Cyclone Energy FATALITIES DAMAGES (2020 Peak USD) 200 888 28.2 32 $415M P a g e | 7 ACKNOWLEGEMENTS & CREDITS

The author would like to thank a few of Force Thirteen re-analysis team for giving some information on Goni’s peak intensity. Another thanks to the Khan Storm Tracking re-analysis team for proofreading the Tropical Cyclone Report before publication.

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http://rammb.cira.colostate.edu/products/tc_realtime/

https://www.ncdc.noaa.gov/gibbs/html/HIM-8/IR/2020-10-30-00 P a g e | 8

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https://rammb-data.cira.colostate.edu/tc_realtime/